Combination Chemotherapy on Primary Lung Adenocarcinoma in an Old Dog

Abstract

A 17-year-old Shih Tzu with a history of mitral valve regurgitation was admitted to the hospital because of coughing and habitual lifting of a left front leg. Radiography revealed a solitary, markedly radio-dense nodule in the left cranial lobe of the lung. Total lobectomy of the tumorous left cranial lobe and removal of the hilar lymph nodes were performed. The diagnosis of pulmonary adenocarcinoma was made on the basis of histopathological findings. Metastasis to the regional lymph nodes was confirmed. Combination chemotherapy with carboplatin and vinblastin sulfate was initiated 10 days after surgery. The mild leucopenia observed a week later necessitated delaying second treatment for seven days. Thereafter the rest of the treatment protocol was carried out without complication. Paresis of the hind limb was observed 90 days after surgery. MRI revealed possible tumor metastasis on the 12th thoracic vertebral body. The dog's condition improved temporarily with administration to prednisolone, but later paresis of the hind limb advanced. The dog's condition deteriorated and it died 196 days after surgery. This case suggests that aggressive treatment can enable an old dog with relatively advanced pulmonary adenocarcinoma to live with a reasonable quality of life. It also suggests that combination chemotherapy with carboplatin and vinblastin sulfate is effective against pulmonary adenocarcinoma.